#include <iostream>
#include <cctype>
int main( )
{
    using namespace std;    //introduces namespace std
    char ch;
    
    cin.get(ch);
    while(ch != '@')
    {
        if (!isdigit(ch))
        {
            if (isupper(ch))
                ch = tolower(ch);
            else if (islower(ch))
                ch = toupper(ch);
            cout << ch;
        }
        cin.get(ch);
    }
    
    return 0;
}
